Clamp down on VS compatibility

Author: shana

src/GitHub.VisualStudio/source.extension.vsixmanifest

@@ -11,7 +11,7 @@
     <Tags>GitHub git github.com team explorer</Tags>
   </Metadata>
   <Installation AllUsers="true">
-    <InstallationTarget Id="Microsoft.VisualStudio.Community" Version="[14.0,]" />
+    <InstallationTarget Id="Microsoft.VisualStudio.Community" Version="[14.0]" />
   </Installation>
   <Dependencies>
     <Dependency Id="Microsoft.Framework.NDP" DisplayName="Microsoft .NET Framework" d:Source="Manual" Version="[4.5,)" />